U.S. patent application number 11/812431 was filed with the patent office on 2008-08-07 for three-phase rotating electrical machine.
This patent application is currently assigned to Mitsubishi Electric Corporation. Invention is credited to Shinji Baba.
Application Number | 20080185933 11/812431 |
Document ID | / |
Family ID | 39675566 |
Filed Date | 2008-08-07 |
United States Patent
Application |
20080185933 |
Kind Code |
A1 |
Baba; Shinji |
August 7, 2008 |
Three-phase rotating electrical machine
Abstract
A magneto generator can be made small in size and light in
weight, and improved in power generation efficiency. The magneto
generator includes an iron core having an iron core main body and a
plurality of teeth (9) radially extending from the iron core main
body, and an armature having a first three-phase winding (14) and a
second three-phase winding (15) comprising winding portions (18u,
18v, 18w, 19a, 19b and 19c) of individual phases wound around the
stator core. The individual first and second three-phase windings
(14, 15) have the winding portions (18u, 18v, 18w, 19a, 19b and
19c) constructed by concentratedly winding conductors around the
individual teeth (9), respectively, while skipping every
predetermined number of teeth (9), and are wound in a state divided
into an inner layer side and an outer layer side, respectively.
Inventors: |
Baba; Shinji; (Tokyo,
JP) |
Correspondence
Address: |
SUGHRUE MION, PLLC
2100 PENNSYLVANIA AVENUE, N.W., SUITE 800
WASHINGTON
DC
20037
US
|
Assignee: |
Mitsubishi Electric
Corporation
Tokyo
JP
|
Family ID: |
39675566 |
Appl. No.: |
11/812431 |
Filed: |
June 19, 2007 |
Current U.S.
Class: |
310/198 |
Current CPC
Class: |
H02K 3/28 20130101; H02K
21/48 20130101; H02K 3/18 20130101; H02K 21/22 20130101 |
Class at
Publication: |
310/198 |
International
Class: |
H02K 27/12 20060101
H02K027/12 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 2, 2007 |
JP |
2007-024234 |
Claims
1. A three-phase rotating electrical machine comprising: an iron
core having an iron core main body and a plurality of teeth
radially extending from said iron core main body; and an armature
having a plurality of sets of three-phase windings comprising
winding portions of individual phases wound around said iron core;
wherein each of said three-phase windings is constructed in such a
manner that said winding portion has a conductor concentratedly
wound around said individual teeth while skipping every
predetermined number of teeth, and at the same time each of said
three-phase windings is wound in a state divided into an inner
layer side and an outer layer side.
2. A three-phase rotating electrical machine comprising: an iron
core having an iron core main body and a plurality of teeth
radially extending from said iron core main body; and an armature
having a plurality of sets of three-phase windings comprising
winding portions of individual phases wound around said iron core;
wherein each of said three-phase windings is constructed in such a
manner that said winding portion has a conductor concentratedly
wound around said individual teeth while skipping every
predetermined number of teeth, and at the same time, each of said
three-phase windings is wound in a state divided into an inner
diameter side and an outer diameter side.
3. The three-phase magneto generator as set forth in claim 1 or 2,
wherein said individual three-phase windings are electrically
connected to commutators separately from each other.
4. The three-phase magneto generator as set forth in claim 1 or 2,
wherein said individual three-phase windings have output lines of
said winding portions of the individual phases connected in
parallel to each other.
5. The three-phase magneto generator as set forth in claim 1 or 2,
wherein said individual three-phase windings have the number of
turns of said conductors of said individual winding portions equal
to one another.
6. The three-phase magneto generator as set forth in claim 1 or 2,
wherein said armature is a stator of a magneto generator.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a three-phase rotating
electrical machine such as for example a magneto generator with an
armature having a plurality of three-phase windings wound around an
iron core.
[0003] 2. Description of the Related Art
[0004] In the past, there has been known a vehicular alternator
with two three-phase windings wound in the same slots (see, for
example, a first patent document: Japanese patent application
laid-open No. 2006-87248 (paragraph No. [0028] on page 7 and FIG.
2).
[0005] In this vehicular alternator, the winding portions of the
individual phases constituting the three-phase windings have
conductors wound up in a waveform beforehand, and are inserted into
slots formed between adjacent ones of a plurality of teeth arranged
to radially extend from an iron core main body so as to be wound
around a fixed stator core.
[0006] In this vehicular alternator, the winding portions are wound
around the stator core in a so-called distributed winding in which
the conductors are wound around the fixed iron core in a
circumferential direction in a state astride nine slots, as shown
in FIG. 2 of the above-mentioned patent document.
[0007] In the case of the winding portions constructed in such a
distributed winding, the conductors protrude from an end face of
the stator core to stride over the nine slots to extend to the
following slot, thus posing the following problem. That is, the
circumferential length of the conductors becomes long, so the
weight thereof is heavy and the electric resistance of the winding
portions increases, resulting in low power generation efficiency of
the magneto coil formed of the winding portions.
[0008] In addition, the height of a coil end of the magneto coil
protruding from an end face of the stator core is high, so there is
also another problem that the axial dimension of a stator having
the magneto coil wound around the stator core is large.
SUMMARY OF THE INVENTION
[0009] Accordingly, the present invention is intended to obviate
the problems as referred to above, and has for its object to obtain
a rotating electrical machine which can be made small in size and
light in weight, and can be improved in the operating efficiency
thereof.
[0010] In one aspect, a three-phase rotating electrical machine
according to the present invention includes an iron core having an
iron core main body and a plurality of teeth radially extending
from the iron core main body, and an armature having a plurality of
sets of three-phase windings comprising winding portions of
individual phases wound around the iron core. Each of the
three-phase windings is constructed in such a manner that the
winding portion has a conductor concentratedly wound around the
individual teeth while skipping every predetermined number of
teeth, and at the same time each of the three-phase windings is
wound in a state divided into an inner layer side and an outer
layer side.
[0011] In another aspect, a three-phase rotating electrical machine
according to the present invention includes an iron core having an
iron core main body and a plurality of teeth radially extending
from the iron core main body, and an armature having a plurality of
sets of three-phase windings comprising winding portions of
individual phases wound around the iron core. Each of the
three-phase windings is constructed in such a manner that the
winding portion has a conductor concentratedly wound around the
individual teeth while skipping every predetermined number of
teeth, and at the same time, each of the three-phase windings is
wound in a state divided into an inner diameter side and an outer
diameter side.
[0012] According to the present inventor, it is possible to make a
three-phase rotating electrical machine small in size and light in
weight as well as to improve the operating efficiency thereof.
[0013] The above and other objects, features and advantages of the
present invention will become more readily apparent to those
skilled in the art from the following detailed description of
preferred embodiments of the present invention taken in conjunction
with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a front elevational view showing a magneto
generator according to a first embodiment of the present
invention.
[0015] FIG. 2 is a cross sectional side view of the magneto
generator of FIG. 1.
[0016] FIG. 3 is an electric circuit diagram of the magneto
generator of FIG. 1.
[0017] FIG. 4 is a front elevational view of essential portions of
the magneto generator of FIG. 1.
[0018] FIG. 5 is a cross sectional arrow view along line V-V in
FIG. 4.
[0019] FIG. 6 is a connection diagram showing a first three-phase
winding of a magneto coil of FIG. 1.
[0020] FIG. 7 is a winding diagram showing the state of winding of
a first three-phase winding wound around a stator core of FIG.
1.
[0021] FIG. 8 is an electric circuit diagram of a modified form of
magneto generator, different from that of FIG. 1, according to the
present invention.
[0022] FIG. 9 is a front elevational view showing essential
portions of the magneto generator according to a second embodiment
of the present invention.
[0023] FIG. 10 is a cross sectional arrow view along line X-X of
FIG. 9.
[0024] FIG. 11 is an electric circuit diagram of a magneto
generator, different from those of FIGS. 1 and 2, according to a
third embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] Now, preferred embodiments of the present invention will be
described in detail while referring to the accompanying drawings.
Throughout respective figures, the same or corresponding members or
parts are identified by the same reference numerals and
characters.
Embodiment 1
[0026] Referring to the drawings and first to FIG. 1, there is
shown, in a front elevational view, a magneto generator according
to a first embodiment of the present invention. FIG. 2 is a cross
sectional side elevational view of the magneto generator of FIG. 1,
and FIG. 3 is an electric circuit diagram of the magneto generator
of FIG. 1.
[0027] This magneto generator, serving as a rotating electric
machine, is provided with a rotor 1 operatively connected with an
internal combustion engine, and a stator 2 disposed at an inner
side of the rotor 1.
[0028] The rotor 1 has a bowl-shaped flywheel 3 and a plurality of
permanent magnets 4 fixedly attached to an inner wall surface of
the flywheel 3. The rotor 1 rotates about an axis of rotation
A-A.
[0029] The permanent magnets 4 are fixedly attached to an inner
peripheral surface of a cylindrical portion of the flywheel 3 at
equal angular intervals with respect to one another around the axis
of rotation A-A by means of molding members 5 (omitted in FIG.
1).
[0030] The plurality of permanent magnets 4 are polarized in such a
manner that adjacent permanent magnets 4 have mutually opposite
polarities, whereby in an inner side space of the permanent magnets
4, there is generated a magnetic field, the direction of which
changes alternately.
[0031] The stator 2 has a hollow cylindrical stator core 6 and a
magneto coil 7. The stator core 6 with its entire surface covered
with an insulating film has an annular iron core main body 8, and a
plurality of teeth 9 protruding from the iron core main body 8
radially in diametrically outer directions at circumferentially
equal intervals.
[0032] A plurality of through holes 10 are formed through the
stator core 6 at circumferential intervals. The stator 2 is fixedly
secured to a non-rotating member in the form of a bracket (not
shown) by means of a plurality of mounting bolts (not shown) that
extend through the through holes 10 to be threaded to the
bracket.
[0033] The stator core 6, serving as an iron core, has a laminated
body 12 that is formed of a multitude of intermediate plates
comprising thin magnetic steel plates (e.g., cold rolled steel
sheets such as SPCC) of a doughnut disk shape laminated one over
another along the direction of the axis of rotation A-A, and a pair
of end plates 13 that are superposed on the opposite side surfaces
of the laminated body 12, respectively, in intimate contact
therewith.
[0034] As shown in FIG. 3, the magneto coil 7 is formed of a first
three-phase winding 14 and a second three-phase winding 15 which
are wound around the stator core 6. The first three-phase winding
14 and the second three-phase winding 15 are individually
electrically connected to commutators 16, respectively, which are
each connected in parallel to a battery 17 and an electric load 22
such as a headlight.
[0035] As shown in FIGS. 4, 5, the first three-phase winding 14 is
arranged at an inner layer side, and the second three-phase winding
15 is arranged at an outer layer side.
[0036] FIG. 6 is a connection diagram of the first three-phase
winding 14, and FIG. 7 is a winding diagram showing the state of
winding of the first three-phase winding 14 wound around the stator
core 6.
[0037] The first three-phase winding 14 at the inner layer side has
individual ends of a U phase winding portion 18u, a V phase winding
portion 18v, and a W phase winding portion 18w connected to one
another in a delta configuration.
[0038] The U phase winding portion 18u is formed by continuously
and concentratedly winding a conductor around individual teeth 9
from No. 1 to No. 16 through No. 4, No. 7, No. 10 and No. 13 in an
anti-clockwise direction while skipping every two teeth 9.
[0039] Similarly, the V phase winding portion 18v is formed by
continuously and concentratedly winding a conductor around
individual teeth 9 from No. 2 to No. 17 through No. 5, No. 8, No.
11 and No. 14 in an anti-clockwise direction while skipping every
two teeth 9.
[0040] Also, the V phase winding portion 18w is formed by
continuously and concentratedly winding a conductor around
individual teeth 9 from No. 3 to No. 18 through No. 6, No. 9 No. 12
and No. 15 in an anti-clockwise direction while skipping every two
teeth 9.
[0041] The first three-phase winding 14 has individual ends of the
U phase winding portion 18u, the V phase winding portion 18v, and
the W phase winding portion 18w connected to one another in a delta
configuration, so that it is connected from this connection portion
to a commutator 16 through output lines 23.
[0042] The second three-phase winding 15 at an outer layer side has
individual ends of an A phase winding portion 19a, a B phase
winding portion 19b, and a C phase winding portion 19c connected to
one another in a delta configuration.
[0043] The A phase winding portion 19a, the B phase winding portion
19b and the C phase winding portion 19c are also formed by
continuously and concentratedly winding the individual conductors
around the corresponding teeth 9, respectively, in an
anti-clockwise direction while skipping every two teeth 9, as in
the case of the U phase winding portion 18u, the V phase winding
portion 18v and the W phase winding portion 18w.
[0044] The second three-phase winding 15 has individual ends of the
A phase winding portion 19a, the B phase winding portion 19b, and
the W phase winding portion 19c connected to one another in a delta
configuration, so that it is connected from this connection portion
to another commutator 16 through output lines 23.
[0045] The individual numbers of turns of conductors for the A
phase winding portion 19a, the B phase winding portion 19b and the
C phase winding portion 19c, respectively, are equal to the
individual numbers of turns of conductors for the U phase winding
portion 18u, the V phase winding portion 18v and the W phase
winding portion 18w, respectively.
[0046] Thus, the number of teeth 9 is eighteen, and the winding
portions 18u, 18v, 18w, 19a, 19b and 19c of the same phases are
constructed by concentratedly winding the individual conductors
around the teeth 9 while skipping every two teeth 9. In addition,
the winding portions 18u, 18v, 18w, 19a, 19b and 19c of the
individual phases are arranged in a positional relation displaced
by one tooth 9 from one another in the circumferential
direction.
[0047] Here, note that, as shown in FIG. 8, a pair of commutators
16 connected to the first three-phase winding 14 and the second
three-phase winding 15, respectively, may be connected in parallel
to each other, and a battery 17 and an electric load 22 may be
connected in parallel to the commutators 16 thus connected in
parallel to each other.
[0048] In the magneto generator as constructed above, the flywheel
3 is rotated in association with a rotation shaft of the rotor
which is driven to rotate by the internal combustion engine, and in
this case, electric power is generated in the first three-phase
winding 14 and in the second three-phase winding 15 by an
alternating field generated by the permanent magnets 4. The ac
outputs thus generated are commutated by the commutators 16, and
are supplied to the vehicle-mounted battery 17 and the electric
load 22.
[0049] As described in the foregoing, according to the magneto
generator of this embodiment, the first three-phase winding 14 and
the second three-phase winding 15 have the winding portions 18u,
18v, 18w, 19a, 19b and 19c of the same phases constructed by
concentratedly winding the individual conductors around the
individual teeth 9 while skipping every two teeth 9, so the length
of the conductors extending across each end face of the stator core
6 becomes short, and the total length of the conductors is
accordingly shortened to a great extent.
[0050] Accordingly, the magneto generator can be made light in
weight, and the electric resistance of the winding portions 18u,
18v, 18w, 19a, 19b and 19c can be reduced, thus making it possible
to improve the power generation efficiency thereof.
[0051] In addition, the height of each coil end of the magneto coil
protruding from a corresponding end face of the stator core becomes
small, so the axial dimension of the stator 2 can be shortened, and
the size thereof can be reduced.
[0052] Further, the first three-phase winding 14 is wound or
arranged at the inner layer side, and the second three-phase
winding 15 is wound or arranged at the outer layer side, with the
different conductors of three-phase windings being continuously and
concentratedly wound around the individual teeth 9, respectively.
With such an arrangement, it becomes possible to freely set the
positions of the starting point and the ending point of each of the
winding portions 18u, 18v, 18w, 19a, 19b and 19c of the individual
phases, so the wire connection work for the respective ends of the
winding portions 18u, 18v, 18w, 19a, 19b and 19c of the individual
phases can be made easy, thereby making it possible to reduce the
cost of production.
[0053] Furthermore, the individual numbers of turns of conductors
for the A phase winding portion 19a, the B phase winding portion
19b and the C phase winding portion 19c, respectively, are equal to
the individual numbers of turns of conductors for the U phase
winding portion 18u, the V phase winding portion 18v and the W
phase winding portion 18w, respectively, so the first three-phase
winding 14 and the second three-phase winding 15 generate
electricity at substantially the same output, and hence are
connected to the commutators 16 of the same specification,
respectively.
Embodiment 2
[0054] FIG. 9 is a front elevational view showing essential
portions of a magneto generator according to the second embodiment
of the present invention, and FIG. 10 is a cross sectional arrow
view along line X-X of FIG. 9.
[0055] In this second embodiment, of three-phase windings, a first
three-phase winding 14 is wound or arranged at an outer diameter
side, and a second three-phase winding 15 is wound or arranged at
an inner diameter side. The other construction of this second
embodiment is similar to that of the first embodiment.
[0056] In this second embodiment, the first three-phase winding 14
is arranged at the outer diameter side, and the second three-phase
winding 15 is arranged at the inner diameter side, with the
different conductors of the three-phase windings 14, 15 being
concentratedly wound around the individual teeth 9, respectively.
With such an arrangement, it becomes possible to freely set the
positions of the starting point and the ending point of each of the
winding portions 18u, 18v, 18w, 19a, 19b and 19c of the individual
phases, so the wire connection work for the respective ends of the
winding portions 18u, 18v, 18w, 19a, 19b and 19c of the individual
phases can be made easy, thereby making it possible to reduce the
cost of production.
[0057] Although in the above-mentioned respective embodiments,
reference has been made to magneto generators in which the first
three-phase winding 14 and the second three-phase winding 15 are
electrically connected to the individual commutators 16 separately
from each other, the present invention can be applied to a magneto
generator in which, as shown in FIG. 11, a first three-phase
winding 14 and a second three-phase winding 15 may be connected in
parallel to each other by means of output lines 23 of individual
phases, and the first and second three-phase windings 14, 15 thus
connected in parallel to each other may be connected to a
commutator 16.
[0058] In addition, the present invention can also be applied to
the first and second three-phase windings 14, 15 with the winding
portions 18u, 18v, 18w, 19a, 19b and 19c of the individual phases
being connected in a Y connection. Moreover, the number of teeth 9
of the stator core 6 need not be limited to 18, but may instead be
3n (i.e., n being an arbitrary integer). Further, the present
invention can also be applied to generators other than magneto
generators or to electric motors in which an armature is rotating.
Furthermore, the present invention may be applied to rotating
electrical machines in which three or more sets of three-phase
windings are wound around an iron core.
[0059] While the invention has been described in terms of preferred
embodiments, those skilled in the art will recognize that the
invention can be practiced with modifications within the spirit and
scope of the appended claims.
* * * * *